feat: backbone first implementation

messages/install.md

@@ -0,0 +1,13 @@
+# summary
+
+Installs a local git merge driver for the given org and branch.
+
+# description
+
+Installs a local git merge driver for the given org and branch, by updating the `.gitattributes` files in the project and creating a new merge driver configuration file in the `.git/config` of the project.
+
+# examples
+
+- Install the driver for a given project:
+
+  <%= config.bin %> <%= command.id %>

messages/uninstall.md

@@ -0,0 +1,13 @@
+# summary
+
+Uninstalls the local git merge driver for the given org and branch.
+
+# description
+
+Uninstalls the local git merge driver for the given org and branch, by removing the merge driver content in the `.gitattributes` files in the project and deleting the merge driver configuration file in the `.git/config` of the project.
+
+# examples
+
+- Uninstall the driver for a given project:
+
+  <%= config.bin %> <%= command.id %>

package.json

@@ -2,7 +2,7 @@
   "name": "sf-git-merge-driver",
   "description": "git remote add origin git@github.com:scolladon/sf-git-merge-driver.git",
   "version": "1.0.0",
-  "exports": "./lib/index.js",
+  "exports": "./lib/service/MergeDriver.js",
   "type": "module",
   "author": "Sébastien Colladon (colladonsebastien@gmail.com)",
   "repository": {

src/commands/git/merge/driver/install.ts

@@ -0,0 +1,21 @@
+import { Messages } from '@salesforce/core'
+import { SfCommand } from '@salesforce/sf-plugins-core'
+import { InstallService } from '../../../../service/installService.js'
+import { UninstallService } from '../../../../service/uninstallService.js'
+
+Messages.importMessagesDirectoryFromMetaUrl(import.meta.url)
+const messages = Messages.loadMessages('sf-git-merge-driver', 'install')
+
+export default class Install extends SfCommand<void> {
+  public static override readonly summary = messages.getMessage('summary')
+  public static override readonly description =
+    messages.getMessage('description')
+  public static override readonly examples = messages.getMessages('examples')
+
+  public static override readonly flags = {}
+
+  public async run(): Promise<void> {
+    await new UninstallService().uninstallMergeDriver()
+    await new InstallService().installMergeDriver()
+  }
+}

src/commands/git/merge/driver/uninstall.ts

@@ -0,0 +1,19 @@
+import { Messages } from '@salesforce/core'
+import { SfCommand } from '@salesforce/sf-plugins-core'
+import { UninstallService } from '../../../../service/uninstallService.js'
+
+Messages.importMessagesDirectoryFromMetaUrl(import.meta.url)
+const messages = Messages.loadMessages('sf-git-merge-driver', 'uninstall')
+
+export default class Uninstall extends SfCommand<void> {
+  public static override readonly summary = messages.getMessage('summary')
+  public static override readonly description =
+    messages.getMessage('description')
+  public static override readonly examples = messages.getMessages('examples')
+
+  public static override readonly flags = {}
+
+  public async run(): Promise<void> {
+    await new UninstallService().uninstallMergeDriver()
+  }
+}

src/constant/driverConstant.ts

@@ -0,0 +1 @@
+export const DRIVER_NAME = 'salesforce-source'

src/index.ts

@@ -0,0 +1,17 @@
+#!/usr/bin/env -S NODE_OPTIONS="--no-warnings=ExperimentalWarning" npx ts-node --project tsconfig.json --esm
+import { MergeDriver } from './service/MergeDriver.js'
+
+if (process.argv.length >= 6) {
+  const [, , ancestorFile, ourFile, theirFile, outputFile] = process.argv
+  const mergeDriver = new MergeDriver()
+  mergeDriver
+    .mergeFiles(ancestorFile, ourFile, theirFile, outputFile)
+    .then(() => process.exit(0))
+} else {
+  console.error('Usage: sf-git-merge-driver %O %A %B %P')
+  console.error('  %O: ancestor file')
+  console.error('  %A: our file')
+  console.error('  %B: their file')
+  console.error('  %P: output file path')
+  process.exit(1)
+}

src/service/JsonMergeService.ts

@@ -0,0 +1,132 @@
+export class JsonMergeService {
+  // Deep merge function for objects
+  mergeObjects(ancestor, ours, theirs) {
+    // If types don't match, prefer our version
+    if (
+      typeof ours !== typeof theirs ||
+      Array.isArray(ours) !== Array.isArray(theirs)
+    ) {
+      return ours
+    }
+
+    // Handle arrays - special case for Salesforce metadata
+    if (Array.isArray(ours)) {
+      return this.mergeArrays(ancestor, ours, theirs)
+    }
+
+    // Handle objects
+    if (typeof ours === 'object' && ours !== null) {
+      const result = { ...ours }
+
+      // Process all keys from both objects
+      const allKeys = new Set([
+        ...Object.keys(ours || {}),
+        ...Object.keys(theirs || {}),
+      ])
+
+      for (const key of allKeys) {
+        // If key exists only in theirs, add it
+        if (!(key in ours)) {
+          result[key] = theirs[key]
+          continue
+        }
+
+        // If key exists only in ours, keep it
+        if (!(key in theirs)) {
+          continue
+        }
+
+        // If key exists in both, recursively merge
+        const ancestorValue = ancestor && ancestor[key]
+        result[key] = this.mergeObjects(ancestorValue, ours[key], theirs[key])
+      }
+
+      return result
+    }
+
+    // For primitive values, check if they changed from ancestor
+    if (theirs !== ancestor && ours === ancestor) {
+      // They changed it, we didn't - use their change
+      return theirs
+    }
+
+    // In all other cases, prefer our version
+    return ours
+  }
+
+  // Special handling for Salesforce metadata arrays
+  mergeArrays(ancestor, ours, theirs) {
+    // For Salesforce metadata, arrays often contain objects with unique identifiers
+    // Try to match items by common identifier fields
+    const idFields = ['fullName', 'name', 'field', 'label', 'id', '@_name']
+
+    // Find a common identifier field that exists in the arrays
+    const idField = idFields.find(
+      field =>
+        ours.some(item => item && typeof item === 'object' && field in item) &&
+        theirs.some(item => item && typeof item === 'object' && field in item)
+    )
+
+    if (idField) {
+      // If we found a common identifier, merge by that field
+      const result = [...ours]
+
+      // Create maps for faster lookups
+      const ourMap = new Map(
+        ours
+          .filter(item => item && typeof item === 'object' && idField in item)
+          .map(item => [item[idField], item])
+      )
+
+      const ancestorMap =
+        ancestor && Array.isArray(ancestor)
+          ? new Map(
+              ancestor
+                .filter(
+                  item => item && typeof item === 'object' && idField in item
+                )
+                .map(item => [item[idField], item])
+            )
+          : new Map()
+
+      // Process items from their version
+      for (const theirItem of theirs) {
+        if (
+          theirItem &&
+          typeof theirItem === 'object' &&
+          idField in theirItem
+        ) {
+          const id = theirItem[idField]
+
+          if (ourMap.has(id)) {
+            // Item exists in both versions, merge them
+            const ourItem = ourMap.get(id)
+            const ancestorItem = ancestorMap.get(id)
+
+            // Find the index in our array
+            const index = result.findIndex(
+              item => item && typeof item === 'object' && item[idField] === id
+            )
+
+            if (index !== -1) {
+              // Replace with merged item
+              result[index] = this.mergeObjects(
+                ancestorItem,
+                ourItem,
+                theirItem
+              )
+            }
+          } else {
+            // Item only exists in their version, add it
+            result.push(theirItem)
+          }
+        }
+      }
+
+      return result
+    }
+
+    // If no common identifier found, default to our version
+    return ours
+  }
+}

src/service/MergeDriver.ts

@@ -0,0 +1,24 @@
+import { readFile, writeFile } from 'node:fs/promises'
+import { XmlMergeService } from './XmlMergeService.js'
+
+export class MergeDriver {
+  async mergeFiles(ancestorFile, ourFile, theirFile, outputFile) {
+    // Read all three versions
+    const [ancestorContent, ourContent, theirContent] = await Promise.all([
+      readFile(ancestorFile, 'utf8'),
+      readFile(ourFile, 'utf8'),
+      readFile(theirFile, 'utf8'),
+    ])
+
+    const mergeService = new XmlMergeService()
+
+    const mergedContent = await mergeService.tripartXmlMerge(
+      ancestorContent,
+      ourContent,
+      theirContent
+    )
+
+    // Write the merged content to the output file
+    await writeFile(outputFile, mergedContent)
+  }
+}

src/service/XmlMergeService.ts

@@ -0,0 +1,45 @@
+import { XMLBuilder, XMLParser } from 'fast-xml-parser'
+import { JsonMergeService } from './JsonMergeService.js'
+
+const options = {
+  attributeNamePrefix: '@_',
+  commentPropName: '#comment',
+  format: true,
+  ignoreAttributes: false,
+  ignoreNameSpace: false,
+  indentBy: '    ',
+  parseAttributeValue: false,
+  parseNodeValue: false,
+  parseTagValue: false,
+  processEntities: false,
+  suppressEmptyNode: false,
+  trimValues: true,
+}
+
+export class XmlMergeService {
+  async tripartXmlMerge(
+    ancestorContent: string,
+    ourContent: string,
+    theirContent: string
+  ) {
+    const parser = new XMLParser(options)
+
+    const ancestorObj = parser.parse(ancestorContent)
+    const ourObj = parser.parse(ourContent)
+    const theirObj = parser.parse(theirContent)
+
+    // Perform deep merge of XML objects
+
+    const jsonMergeService = new JsonMergeService()
+    const mergedObj = jsonMergeService.mergeObjects(
+      ancestorObj,
+      ourObj,
+      theirObj
+    )
+
+    // Convert back to XML and format
+    const builder = new XMLBuilder(options)
+    const mergedXml = builder.build(mergedObj)
+    return mergedXml
+  }
+}

src/service/installService.ts

@@ -0,0 +1,23 @@
+import { appendFile } from 'node:fs/promises'
+import { simpleGit } from 'simple-git'
+import { DRIVER_NAME } from '../constant/driverConstant.js'
+
+export class InstallService {
+  public async installMergeDriver() {
+    const git = simpleGit()
+
+    await git
+      .addConfig(`merge.${DRIVER_NAME}.name`, 'Salesforce source merge driver')
+      .addConfig(
+        `merge.${DRIVER_NAME}.driver`,
+        'node ${__dirname}/index.js %O %A %B %P' // TODO define how to do that
+      )
+      .addConfig(`merge.${DRIVER_NAME}.recursive`, 'true') // TO CHALLENGE
+
+    const content =
+      ['*.xml'].map(pattern => `${pattern} merge=${DRIVER_NAME}`).join('\n') +
+      '\n'
+
+    await appendFile('.gitattributes', content, { flag: 'a' })
+  }
+}

src/service/uninstallService.ts

@@ -0,0 +1,20 @@
+import { readFile, writeFile } from 'node:fs/promises'
+import { simpleGit } from 'simple-git'
+import { DRIVER_NAME } from '../constant/driverConstant.js'
+
+const MERGE_DRIVER_CONFIG = new RegExp(`.* merge\\s*=\\s*${DRIVER_NAME}$`)
+
+export class UninstallService {
+  public async uninstallMergeDriver() {
+    const git = simpleGit()
+    await git.raw(['config', '--remove-section', `merge.${DRIVER_NAME}`])
+
+    const gitAttributes = await readFile('.gitattributes', {
+      encoding: 'utf8',
+    })
+    const filteredAttributes = gitAttributes
+      .split('\n')
+      .filter(line => !MERGE_DRIVER_CONFIG.test(line))
+    await writeFile('.gitattributes', filteredAttributes.join('\n'))
+  }
+}